Improvement in furnaces for roasting and smelting ores



2 Sheets--Sheet 1r V L'. STEVENS. Furnaces for Roasting and Sm 141,181.

elting Dres. Patentedjuly 22 AM. P/mm-urHoGnAPH/c v0. N.Y. asso/m51? macias) 2 Sheets--Sheet 2.

Patented Juy 22,1873.

Vit messes AM. PHorn-ur/msRAPH/c ca MWOsEaRNE Pnocsss) `N1TED STATES PATENT CFFIoa.

LEVI STEVENS, OF WASHINGTON, DISTRICT OF COLUMBIA.

IMPROVEMENT IN F'URNACES FOR ROASTING AND SMELTING CRES.

Specification forming part of Letters Patent No. 141,181, dated July 22, 1873; application filed January 17,1873.

' science to which it most nearly appertains to make and use my said invention without further invention or experiment.

My invention relates to an improved furnace for roasting and smeltin g ores; and it consists, mainly, in a novel combination of a roasting or desulphurizing fiue, having a suitable feeding device, with an inclined snielting-ue, having at its base a suitable chamber for receiving and separating the slag and metal and discharging the same. My invention further consists in apeculiarly-constructed furnace for burning, and a device for introducing, carbonic oxide, which is formed by processes for which United AStates Letters Patent were granted to me February 21, 1871, and numbered 112,088, and also October 15, 1872, and numbered 132,331. The heat from this furnace passes successively through the smelting-Hue and the roasting-due, and a superheater is so placed that it is also heated by the same re. Steam from this superheater is introduced to the furnace with the combustible gases by my apparatus, and a pipe is so arranged as to lead a part of the steam to the roasting-flue, where it is used when desired. Dampers are so arranged that the heat is directed into either flue or chimney, as desired, and the supply of air to the furnace is regulated by a cock.

Referring to the accompanying drawings for a more complete explanation of my invention, Figure l is a side elevation of my furnace. Fig. 2is a sectional elevation, showing the interior-y arrangement. Fig. 3 is an end view. Fig. 4 is an enlarged View of the supply apparatus for the furnace. Fig. 5 is a crosssection of the roasting-liuc.

A is a chamber, into which the inammable gases and vapors are first received from the supply apparatus, and from this chamberthey pass into the combustion-chamber, where they unite and are burned. The chamber A is closed tightly at the front where the gas enters, and has a diaphragm, a, extending horizontally across, just beneath the inductionpipe. This diaphragm is constructed with a passage from its lower to its upperside, the passage being at its, rear end, as shown. 'j his passage admits air, when desired. Between the chamber A and the combustionchamber B a deiector, b, is formed. This dellector may stand at right angles, or it mayv incline upward or downward at such an angle as shall be found most suitable. Its oice isA to partially arrest the current of combustible gas which is discharged from the nozzle of the supply apparatus with immense velocity, and thus insure its being ignited at the instant of entering the chamber B, and, further, to deiiect the current and direct it as may be desired in a reverberatory or other form of furnace. From the chamber B the heat and products of combustion pass up the inclined iiue D. The upper end of this ilue opens into a chimney, E, and has also a passage connecting it with the inclined ue F, having a crosssection as shown in Fig. 5. The upper end of the flue F opens into a second chimney, G,

and at this point is the feed-opening g, from which the ore is discharged, by any suitable device, into the flue F. A shaft, H, passes longitudinally through this due, and propellervanes I are secured upon the shaft, so that when it is rotated the propellers gradually force the ore down the incline, stirring it thoroughly at the same time' until it reaches the lower end, when it will be thoroughly roasted and desulphurized. The shaftll may be driven by a worm-wheel and belt from the source of power, or by any suitable mechanical device. A damper, J, serves to turn all or part of the heat into the flue E, as may be desired. The ore, being thus prepared in the flue F for smelting, is discharged from its lower end into the ue D, which stands at an inclination considerably greater than that of the iue F. Down this due the ore passes, the heat becoming more and more intense, and it is thus smelted, and by the motion the metal is separated from the slag and all the particles are brought together so that they will unite by their attraction. This allows the body of metal to fall to the bottom of the chamber B, from which it can be drawn off by a suitable opening, K. Other 2 rumen openings, L, are arranged For the discharge of the slag. The furnace will be heated wholly1 or in part by my improvement in heating-furnaces, the apparatus for which is shown at Fig. 4. M is a pipe, which brings the gases (protoxide of carbon and hydrogen) to the furnace from the retorts. The pipe M discharges into the air-pipe N, which in turn opens into the furnace through the nozzle 0. A pipe, P, brings steam from the superheater 1t, and this pipe opens into the rear end ot' the nozzle in a line with its discharge-opening, so that steam from the pipe mingles with the gases before mentioned and gives additional force to the discharge. is provided with a regulating-cock, S, which I place, preferably, behind the point at which the pipe M enters the air-pipe, and by means of this cock the supply of oxygen from the air is regulated, and I am thus enabled to govern the heatof the furnace exactly and to suit it to the needs of the particular class of ore under treatment. The superheater R is so placed that a portion of the heat from the com bustion-chamber can bc utilized for superheating the steam, and a pipe from the superheater opens into the flue F, Where steam can sometimes be used to assist the process. The

whole arrangement is simple and economical.

Stairs T serve to give access to a platform, U, by the side of the ue F, and from the stairs and platform the progress of the Work The air-pipe N can be examined from time to time through suitable openings in the tlues l) and F.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. The combination, in a roasting and smelting furnace, of the inclined tlues F and l) with a single heating-furnace and regulating-dam pers, when constructed and arranged to operate substantially as described.

2. The inclined flue F, provided with the revolvin g worm or screw l, arranged to feed the ore gradually to the inclined flue D, substanv and seal.

LEVI STEVENS. [1.. srl' Witnesses GEO. H. STRONG, C. M. RrcHARDscN. 

